The projects in this continuation proposal are part of a series of investigations seeking ways to develop and harness search strategies ("hedges") that will improve retrieval of clinically relevant and scientifically sound study reports from large, general purpose, biomedical research bibliographic databases including MEDLINE, EMBASE, PsycLIT, and CINAHL. The long-term objective is to harness the most clinically relevant content of these electronic databases so that their effects on clinical practice can be eventually tested. In our previous research Using MEDLINE, we documented the retrieval performance of over 60,000 "methodologic hedges", that is, search strategies designed to detect applied clinical research studies that meet key scientific standards for validity and applicability to clinical practice. A project is currently underway to extend this research in recent MEDLINE files and in EMBASE, PsycLIT, and CINAHL. The database created in this research can be used to answer new questions, specifically: A) What are the operating characteristics, in year 2000 files of MEDLINE, EMBASE, PsycLIT, and CINAHL, of methodologic terms that define studies of the most importance to clinical questions about the economic aspects of human disorders, to questions about clinical prediction, and to clinical questions that lead to a review of the literature? B) What are the operating characteristics in these electronic databases of individual age-related terms for retrieving studies of a particular age-specific area of medicine, and how do the top yielding strategies perform when combined with top yielding methodologic search strategies? C) For diverse clinical content areas, to what extent are articles clustered in journal subsets, and how is the precision of searching affected when running searches in journal subsets? D) What is the correlation between journal impact factors and yield from the journals included in our hand searched database? To create and evaluate the search strategies, index terms and text words are treated as 'diagnostic tests' and a hand search of the literature is treated as the 'gold standard'. Articles are defined as having relevant content and meeting basic methodologic criteria for clinical practice by the hand search. The operating characteristics of these strategies are determined in the 4 electronic databases.